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Hi fellas, I'm new the forum and sorry for asking questions about the 2003 Z06 I bought last week. Before I bought it, I didn't know of the few issues these cars came with. First and foremost worriesome threads I saw on the forum was the dreaded valve spring failure and second one was the harmonic balancer failure.
My car built date is 5/03 with last 5 digits in the 32000 range. I tried to look at the valve springs through the oil filler neck but very little portion of it is not yellow. Maybe paint came off of it. Car has little ticking sound when accelerating but seems like similar to few pushrod cars I had previously. Always a some sort of ticks with pushrod motor whether ford or chevy regardless. Car has 28K miles, mgw short throw shifter, after market big mouth air dam, and borla exhaust. It is a beautiful and most exciting car I've ever driven. I owned few mustang cobras but this z06 is in different class compared to fords I've owned.
I've included video or my harmonic balancer. There is a little wobble but no belt chirping or etc. I was wondering what guys think if I need a new one. Any input will be greatly appreciated.
Yea, I know what you mean. When I got my 03' Z I had no idea of the faulty products used to build these machines.
I changed my valve spring from the yellow to blue and did the trunnion upgrade. You are going to have open up the valve cover to see what you have unless you can contact the previous owner. Also, put in a oil catch can because when you clean out your intake you will be surprised at the amount of gunky oil in there.
I'm in the process of changing my harmonic balancer to an ATI unit with an ARP bolt. There are other less expensive brands, but I just want to do this once. Also, "while you're in there" you might as well change out the timing chain. I'm going with the Katech C5-R chain. Again, once is enough.
There is a whole list of things to do to the C5 to make it more reliable. If you plan to track the car and do HPDEs, I've got a long list of things to do to the car to help it stay together.
Send me a message if want my laundry list. Good luck.
Spaggs
Thank you so much for your reply and advice. I love this car the way it is. It is by far best driving machine I've ever owned. I owned plenty of fast cars and this one is above it all! So impressed with z06.
I was able to get a snake camera and see a little of valve springs and rockers. Is the rocker on picture stock? And springs are not yellow. Also, there's a pic of blue valve cover gasket. Did stock car come with blue valve cover gasket? Did i get lucky and previous owner changed springs and rockers? It has 1.7 written on top.
If you paint a line across the balancer from the center to outside edge you can easily see if the outer rim is moving. If the line stays straight its likely fine. If you see the outer rim moves its time for a new balancer. The rocker arms are probably fine. The springs are a gamble some have no issues and others have reported broken springs. The car is 16 years old and even with low miles you need to think about plugs and wires, check grounds and other routine maintenance items.I bought a 2001 Z06 with 27,000 miles on it and had several problems the first few months I owned it. Balancer, starter wiring, AC display unit, head lights not staying down. Once you the little things fixed they are pretty dependable cars.
Thanks for the reply. I made a paint mark across the HB few days ago and drove it for a while. Marks are straight, not separated. It's a ever so slight wobble or can even be discoloration illusion I'm seeing. I looked at the balancer by lining up flush against the belt tensioner pulley and they both remained straight while both were spinning. But I still ordered a new racing HB by powerbond and have it near so I can get it swapped out when wobble does get worse or line marker moves. Local speed shop quoted me 850 - 1250 for the labor since it's an extensive job of removing steering rack etc. I know it's lot of money for labor but what can I do, I just live in area of US where every damn things are expensive. Valve springs are rockers are definitely aftermarket so at least I don't need to spend money for that.
Those dont look like stock rockers to me. Good bet springs changed too, but I would pull a valve cover, its really easy to do. Google the valve spring change, plenty of videos to help you get in there and check. Someone may be able to ID the rockers and springs for you.
Those dont look like stock rockers to me. Good bet springs changed too, but I would pull a valve cover, its really easy to do. Google the valve spring change, plenty of videos to help you get in there and check. Someone may be able to ID the rockers and springs for you.
LOL!! I AGREE!! Yea,, that was my thoughts too! Rockers look aftermarket! I bet it has a different cam too! Dampener look good to me. I didn't see any appreciable wobble. Like BTTBSS stated,, paint a white line on the FRONT of the assembly across the outer ring, rubber and the hub. If you notice that the white line ever starts to no longer line up, the rubber has become de-bonded from the parts and its time for a new one.
Clear ALL of the DTCs using the internal DIC code reader and monitor. Report the DTCs that come back.
Bill
Last edited by Bill Curlee; Apr 23, 2019 at 02:02 PM.
2003 Z06 Issues
Yea,, that was my thoughts too! Rockers look aftermarket! I bet it has a different cam too! Dampener look good to me. I didn't see any appreciable wobble. Like BTTBSS stated,, paint a white line on the FRONT of the assembly across the outer ring, rubber and the hub. If you notice that the white line ever starts to no longer line up, the rubber has become de-bonded from the parts and its time for a new one.
